Pertanika 6(3), 107-110 (1983)

COMMUNICATION (1)

Free Flow Traffic Noise in Three Malaysian Cities

RINGKASAN

Kertas ini melaporkan suatu kajian mengenai paras bunyi lalulintas di tiga buah bandar besar diSemenanjung Malaysia. Pada keseluruhannya, paras bunyi yang diperolehi adalah tinggi dan mempunyaihubungan rapat dengan keadaan lalulintas. Cadangan untuk mengatasi masalah ini juga telah diberikan.

SUMMARY

This paper reports a study on free flow traffic noise in three cities in Peninsular Malaysia. It isfound that generally the noise level is high and correlates with the type of traffic. A few suggestions oncontrol measures are made.

INTRODUCTION

In an urban environment the major sourcesof noise associated problems originate from motorvehicles which generate power as high as twentytimes more than all other sources combined(Bugliarello, 1976). Although noise levels varywith different types of vehicle in a steady trafficflow the noise generated attains an almost con­stant level, with noise emitted by certain vehicles(such as heavy trucks, lorries, buses and motor­cycles) being predominant. Stephenson and Vulkan(1968) have pointed out that these vehiclesproduce noise up to twice as loud as that fromprivate cars.

In Malaysia, studies on traffic noise have beenlimited to the two major cities of Kuala Lumpur(Yeow et aL, 1972, Terazaki and Fukuhara,1979) and Penang (Tan, 1982). Their studies haveshown that although the noise level is lower thanthat found in many other Asian cities, in someareas, however, the levels were as high as thosefound in Los Angeles and New York (Kimotoand Fukuhara, 1980). The very rapid increasein the number of motor vehicles on Malaysianroads will undoubtedly increase traffic noise in thefuture. Studies and surveys of the present noiseclimate will provide very useful data especiallyfor town planners and developers of land use.

METHOD

In this study, the noise levels at 76 samplingsites covering the urban areas of Kuala Lumpur,Seremban and Johar Bahru were measured usingthe noise level analyzer. (Bruel and Kjaer type

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4426). Measurement sites were chosen on straight,level roads away from traffic interruptions suchas road junctions, traffic lights or pedestriancrossings. Roads with reflecting surfaces such astall buildings and trees were avoided.

At each site the noise level was measured at0.2s intervals for 1000 seconds and its mean levelwas calculated. The number of passing vehicleswere counted simultaneously and grouped intotwo main categories (Lewis, 1973) namely heavyvehicles which included lorries, buses and motor­cycles, and light vehicles consisting of cars, vansand pick-ups. To obtain an average daytimenoise level, measurements were made during thenormal traffic conditions on working days. Peakhours of 0800-0900 hrs, 1200-1400 hrs and1600-1800 hrs were avoided. However, wholedaytime hourly measurements were made at afew selected sites.

RESULTS AND DISCUSSIONS

A summary of the mean noise levels is shownin Table 1. The mean level in Kuala Lumpur wasfound to be the highest among the three areas. Inthe town centre the mean level in Kuala Lumpurranged from 71.9 to 75.9 dBA, in Johor Bahrufrom 64.3 to 69.2 dBA and in Seremban from64.1 to 67.5 dBA. The levels were seen to decreaseat sites further from the town centre and frommain roads leading to the town centre.

A typical daytime variation of the noiselevel at Kuala Lumpur is shown in Figure 1. Themean levels remained fairly constant, within the73-74 dBA range during the whole measurement

ZAINAL ABIDIN SULAlMAN AND ELIAS SAlON

TABLE 1Summary of mean noise level (in dBA)

Category of Location

Town centre, commercial

Main roads, commercial

Sub-urban, residential andlight industries

Suburb, residential

Kuala Lumpur

71.9-75.9

67.4-73.6

Seremban

64.1-67.5

61.9-65.5

56.7-62.7

53.6-56.0

Johor Bahru

64.3-69.2

61.8-65.7

57.5-64.5

53.6-55.4

74

72

Jalan Kucing, Kuala Lumpur28th August 1982

)(.

I.

II

II

II

I.}t.-- - - - -_.~

~ noise level

~ no. of vehicles

§x

6.0 u

~

'- ~ ----L '__ _+_ __'_ ___'L__ "'__ ....L_ __'_ IS.O

mOrning 10 II 12 13

Time

14 15 16 17 18 evening

Fig. 1. A typical daytime variation of noise level and traffic volume.

time with a slight increase during the rush hours(1200-1400 hrs. and 1600-1800 hrs.). The 24hour pattern of continuous measurements inKimoto and Fukuhara (1980) study for thesame area featured a high noise level from about0700 hrs. until around 2100 hrs. and fell to about5-10 dBA below the mean daytime level aftermidnight until around 0700 hrs. the next morning.No wholeday measurements were made in JohorBahru and Seremban.

Figure 1 also shows the relation betweennoise level and traffic volume. In general thenoise level was higher for greater traffic volumes.Figure 2 indicates that the noise level increasedlinearly at first as the traffic volume increasedat the rate of about 5 dBA for every two-foldincrease in traffic volume. The increase thenbecame more gradual, and for traffic volumes

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greater than about 3500 vehicles per hour, thelevel became almost constant irrespective of theincrease in the number of vehicles. The workof Stephenson and Vulkan (1966) for Londontraffic showed a similar pattern.

Attempts were also made to determine thedependence of noise level on the traffic composi­tion, but there were insufficient data for a statisti­cally significant conclusion. However, it wasnoted that the levels were slightly higher for ahigher percentage of heavy vehicles of the sametraffic volume.

CONCLUSION

The findings in this study show that trafficnoise problems do exist in these three townsbut are confined to the central commercial areas.

FREE FLOW TRAFFIC NOISE IN THREE MALAYSIAN CITIES

75

70

-;{m~ 65

oc 60

55

o 0co o

oo

Number of vehicle~; per hour I X 1000}

Fig. 2. The relationship between noise level and traffic volume.

By United Kingdom standards, these levels arefar above the acceptable limit. The traffic noisestandard in the U.K. is 68 dBA using the LlO 18hindex, where the level exceeds 10% of the timemeasured hourly between 0600 and 2400 hrs.In Malaysia, acceptable levels are yet to be formu­lated. Under the provisions of the motor vehicles(Construction and Use) Rules 1959, it is a statutoryrequirement for motor vehicles to be equippedwith silencers and for their maintenance; andprovisions exist for motorists to be prosecutedfor making excessive noise by using defectivevehicles. But this legislation sets no specific noiselimits and hence makes enforcement difficult.

In view of the present growth of trafficvolume, the problem could become more seriousin the near future. There is a need for moreprecise legislation on noise control, including theimposition of a statutory acceptable noise limitfor all new motor vehicles manufactured, as ismandatory in many countries; or by zoningspecific areas where traffic have to conform to

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stipulated noise limits as is commonly done inJapan.

Zainal Abidin Sulaiman and Elias Saion

Jabatan Fizik,Universiti Pertanian Malaysia,Serdang, Selangor.

REFERENCES

BUGLIARELLO. G. (1976): The impact of noise pollu­tion. Pergamon Press.

GOVT. OF MALAYSIA. (1959): "Road traffic Act1959". Section on 'Motor Vehicle (Constructionand Use) Rules'.

KIMOTO. S., and FUKUHARA. H., (1980): Noise inKuala Lumpur. Repts ofEnviron. Sci and Tech. Lab.Oita Inst. of Tech. 3, 33-39.

LEWIS. P.T., (1973): The noise generated by singlevehicle in freely flowing traffic. 1. Sound Vib.30(2),191-206.

ZAINAL ABIDIN SULAIMAN AND ELIAS SAlON

STATUTORY INSTRUMENT, (1973): No. 1363: TheNoise Insulation Regulations, HMSO. London.

STEPHENSON, R.J., and VULKAN, G.H., (1968):Traffic Noise. J. Sound Vib. 7(2): 247-262.

TAN, G.L., (1982): Noise in Penang. Paper presented atAcoustic Seminar, Universiti Teknologi Malaysia.Kuala Lumpur.

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TERAZAKI, T.D., and FUKUHARA, H. (1979): Noise inKuala Lumpur. Universiti Teknologi Malaysia.

YEOW, K.W., ONG, W.T., NG, S.F., LOH, S.H. andMAH, L., (1972): The traffic noise problem inMalaysia. Paper presented at symposium on therole of the engineer in environmental pollutioncontrol. Kuala Lumpur.

(Received 4 May 1983)